Chemical Reactions and Equations

Flashcards covering key terms and concepts related to chemical reactions and equations.

Reactants

Substances that are present before a chemical reaction; found on the left-hand side (LHS) of a chemical equation.

Products

Substances that are formed as a result of a chemical reaction; found on the right-hand side (RHS) of a chemical equation.

Balanced Equation

An equation in which the number of atoms of each element is the same on both sides.

Diatomic Molecules

Molecules made up of two atoms, often referring to elements that naturally exist as pairs (e.g., H2, O2).

Combination Reaction

A chemical reaction where two or more substances combine to form a single product (e.g., A + B → AB).

Decomposition Reaction

A chemical reaction in which a single compound breaks down into two or more simpler products (e.g., AB → A + B).

Single Replacement Reaction

A reaction where one element replaces another in a compound (e.g., A + BC → B + AC).

Double Replacement Reaction

A reaction where the parts of two compounds swap and form two new compounds (e.g., AB + CD → AD + BC).

Combustion Reaction

A reaction where a hydrocarbon reacts with oxygen to produce carbon dioxide and water, usually accompanied by heat (e.g., hydrocarbon + O2 → CO2 + H2O + heat).

Redox Reaction

A chemical reaction that involves the transfer of electrons between two species, where one substance is oxidized and another is reduced.

Exothermic Reaction

A reaction that releases heat, resulting in a temperature increase in the surroundings (e.g., combustion reactions).

Endothermic Reaction

A reaction that absorbs heat, resulting in a temperature decrease in the surroundings.

Mole (mol)

A unit that represents 6.022 x 10^23 particles (Avogadro's number), commonly used to express quantities in chemistry.

Molar Mass

The mass of one mole of a substance, usually expressed in grams per mole (g/mol).

Limiting Reactant

The reactant that is fully consumed in a reaction, determining the maximum amount of product that can be formed.

Percent Yield

A measure of the efficiency of a reaction, calculated as (experimental yield / theoretical yield) x 100%.

Empirical Formula

The simplest whole-number ratio of atoms of each element in a compound.

Molecular Formula

The formula that indicates the actual number of atoms of each element in a molecule of the compound.